How to paint a gradient with TexDraw brush?
Strokes set to Line do not give you the ability to see a gradient travel along it, or curve for that matter. TexBrush with gradient and pressure in the Strength ticked on (be sure to adjust the strength to allow for some fluctuation) can be useful for changing the color along the gradient ramp, but then it is really about using your manual stroke here to control the pressure - wit hthat, I sometimes play with the Shift-S Smooth Stroke or Lazy Stroke to control my line/curve while painting.